Space research is helping to cut back on visits to the dental chair with the introduction of shape memory alloys (SMAs). These 'smart' metals have an amazing ability to 'remember' different positions.
Just like an elastic band, they return to their original form after being stretched or folded. If they are bent into a new shape, then applying heat makes them return to the way they were.
The European space programme developed these alloys for automated switches. However, they soon found many uses, including the repair of broken bones.
Staples made from bent SMA wire are fixed across a fracture. Body heat then causes the staples to close, thus drawing the bones together.
They not only close the break but also strengthen the bone until it heals. In the same way, they can be used to control the movement of teeth.
About a quarter of all children need to visit a dentist to improve the arrangement of their teeth. By using SMAs, it is now possible to close gaps between teeth or straighten them gently but quickly. This means less pain and fewer visits to the dental surgery.
Last update: 12 October 2011